Unmanned aerial vehicle (UAVs), also referred to as “drones,” are commonly used for crop inspections, power line inspections, security applications, communication aerostats and a host of other applications. Fixed wing drones reduce their energy requirements by relying on aerodynamic lift, rather than thrust from rotors, to remain aloft. This significantly reduces power requirements to the point that high efficiency solar cells are able to provide sufficient power to maintain altitude while the drone is in direct sunlight. Sunlight provides 1000 watts of energy per square meter, and thus with a ˜30% efficient solar cell, up to 300 watts can be harvested per square meter of surface area. Such solar powered systems do encounter challenges at night or when the sun is obstructed. Alternatively, drones can be configured to receive terrestrial-based power beams via infrared lasers. For example, power transfer via near-IR laser beam can be relatively efficient and may have a higher intensity than solar. However, in order to take advantage of terrestrial-based power beaming, a drone's flight path must be restricted to routes within range of stations with terrestrial-based power beaming emitters.
Traditional fixed wing drones primarily use control surfaces to adjust the drone's attitude, which attitude determines performance (based on airspeed, atmospheric conditions, etc.). In contrast, drones that primarily use thrust to adjust attitude, like quad-copters, do not have this requirement; flight is possible in many attitudes, with the usual goal being the most efficient flight possible. However, drones that primarily use lifting surfaces to adjust attitude may have some flight modes requiring the drone to remain as “flat” as possible, such as for crop photography/spectroscopy, with the rotors used to maintain the desired drone attitude through turns, climbs, and descents. Such flight modes may require the decoupling of drone attitude versus flight path.